The epidemiological study described in this proposal is based on nearly 1000 interviews of mothers of randomly sampled children ages 1 to 10. Data were collected with regard to the children's emotional and behavioral problems and competencies, children's health histories, child rearing and other family structure and environmental variables in the original wave of data collection during 1975. Psychometric and substantive studies of these data will have been completed during the current grant period. Follow up interviews of both mothers and children have been carried out when the children were ages 9 to 18. The reinterviews included DSM III based diagnostic interviews, scales derived from the original interviews, and extensive data on familial and extrafamilial environment. In addition, a reinterview of 100 families to provide a clinical validation will have been completed to provide the basis for assessment and improvement of the lay diagnostic interviews. The specific aims for the current proposal include psychometric investigations into methodological issues in diagnosis. Improvements in the diagnostic instrument based on these analyses will then be applied in a new wave of data collection in which mothers and children will again be interviewed with a structured instrument designed to cover the same issues addressed in the current wave. In addition, a reinterview of a sample of the older children, now ages 15 to 20, will be carried out with the adult DIS. This substudy will enable a translation of diagnosis across instruments and comparison of this sample with other available samples. The data will be employed to determine the prevalence and persistance of psychiatric disorders in children and their antecedents in the problems of early childhood. Data collected at all three points in time will be employed to determine risk factors and concomitants of psychopathology. In addition, the study will assess the generality of these risk factors and their relative potencies for children living in different extra-familial environments. The data analysis will include replication of previous findings suggesting differential environmental effects, and testing of theoretically and empirically and derived models.